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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/ipc/shm.c | |
3 | * Copyright (C) 1992, 1993 Krishna Balasubramanian | |
4 | * Many improvements/fixes by Bruno Haible. | |
5 | * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994. | |
6 | * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli. | |
7 | * | |
8 | * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com> | |
9 | * BIGMEM support, Andrea Arcangeli <andrea@suse.de> | |
10 | * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr> | |
11 | * HIGHMEM support, Ingo Molnar <mingo@redhat.com> | |
12 | * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com> | |
13 | * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com> | |
14 | * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com> | |
15 | * | |
073115d6 SG |
16 | * support for audit of ipc object properties and permission changes |
17 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> | |
4e982311 KK |
18 | * |
19 | * namespaces support | |
20 | * OpenVZ, SWsoft Inc. | |
21 | * Pavel Emelianov <xemul@openvz.org> | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/slab.h> |
25 | #include <linux/mm.h> | |
26 | #include <linux/hugetlb.h> | |
27 | #include <linux/shm.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/file.h> | |
30 | #include <linux/mman.h> | |
1da177e4 LT |
31 | #include <linux/shmem_fs.h> |
32 | #include <linux/security.h> | |
33 | #include <linux/syscalls.h> | |
34 | #include <linux/audit.h> | |
c59ede7b | 35 | #include <linux/capability.h> |
7d87e14c | 36 | #include <linux/ptrace.h> |
19b4946c | 37 | #include <linux/seq_file.h> |
3e148c79 | 38 | #include <linux/rwsem.h> |
4e982311 | 39 | #include <linux/nsproxy.h> |
bc56bba8 | 40 | #include <linux/mount.h> |
ae5e1b22 | 41 | #include <linux/ipc_namespace.h> |
7d87e14c | 42 | |
1da177e4 LT |
43 | #include <asm/uaccess.h> |
44 | ||
45 | #include "util.h" | |
46 | ||
bc56bba8 EB |
47 | struct shm_file_data { |
48 | int id; | |
49 | struct ipc_namespace *ns; | |
50 | struct file *file; | |
51 | const struct vm_operations_struct *vm_ops; | |
52 | }; | |
53 | ||
54 | #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) | |
55 | ||
9a32144e | 56 | static const struct file_operations shm_file_operations; |
f0f37e2f | 57 | static const struct vm_operations_struct shm_vm_ops; |
1da177e4 | 58 | |
ed2ddbf8 | 59 | #define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) |
1da177e4 | 60 | |
4e982311 KK |
61 | #define shm_unlock(shp) \ |
62 | ipc_unlock(&(shp)->shm_perm) | |
1da177e4 | 63 | |
7748dbfa | 64 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
65 | static void shm_open(struct vm_area_struct *vma); |
66 | static void shm_close(struct vm_area_struct *vma); | |
4e982311 | 67 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 68 | #ifdef CONFIG_PROC_FS |
19b4946c | 69 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
70 | #endif |
71 | ||
ed2ddbf8 | 72 | void shm_init_ns(struct ipc_namespace *ns) |
4e982311 | 73 | { |
4e982311 KK |
74 | ns->shm_ctlmax = SHMMAX; |
75 | ns->shm_ctlall = SHMALL; | |
76 | ns->shm_ctlmni = SHMMNI; | |
77 | ns->shm_tot = 0; | |
e8148f75 | 78 | ipc_init_ids(&shm_ids(ns)); |
4e982311 KK |
79 | } |
80 | ||
f4566f04 | 81 | /* |
3e148c79 ND |
82 | * Called with shm_ids.rw_mutex (writer) and the shp structure locked. |
83 | * Only shm_ids.rw_mutex remains locked on exit. | |
f4566f04 | 84 | */ |
01b8b07a | 85 | static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
4e982311 | 86 | { |
01b8b07a PP |
87 | struct shmid_kernel *shp; |
88 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
89 | ||
4e982311 KK |
90 | if (shp->shm_nattch){ |
91 | shp->shm_perm.mode |= SHM_DEST; | |
92 | /* Do not find it any more */ | |
93 | shp->shm_perm.key = IPC_PRIVATE; | |
94 | shm_unlock(shp); | |
95 | } else | |
96 | shm_destroy(ns, shp); | |
97 | } | |
98 | ||
ae5e1b22 | 99 | #ifdef CONFIG_IPC_NS |
4e982311 KK |
100 | void shm_exit_ns(struct ipc_namespace *ns) |
101 | { | |
01b8b07a | 102 | free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
7d6feeb2 | 103 | idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr); |
4e982311 | 104 | } |
ae5e1b22 | 105 | #endif |
1da177e4 LT |
106 | |
107 | void __init shm_init (void) | |
108 | { | |
ed2ddbf8 | 109 | shm_init_ns(&init_ipc_ns); |
19b4946c MW |
110 | ipc_init_proc_interface("sysvipc/shm", |
111 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", | |
4e982311 | 112 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
113 | } |
114 | ||
3e148c79 ND |
115 | /* |
116 | * shm_lock_(check_) routines are called in the paths where the rw_mutex | |
00c2bf85 | 117 | * is not necessarily held. |
3e148c79 | 118 | */ |
023a5355 | 119 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 120 | { |
03f02c76 ND |
121 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
122 | ||
b1ed88b4 PP |
123 | if (IS_ERR(ipcp)) |
124 | return (struct shmid_kernel *)ipcp; | |
125 | ||
03f02c76 | 126 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
127 | } |
128 | ||
129 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
130 | int id) | |
131 | { | |
03f02c76 ND |
132 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
133 | ||
b1ed88b4 PP |
134 | if (IS_ERR(ipcp)) |
135 | return (struct shmid_kernel *)ipcp; | |
136 | ||
03f02c76 | 137 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
1da177e4 LT |
138 | } |
139 | ||
7ca7e564 | 140 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 141 | { |
7ca7e564 | 142 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
143 | } |
144 | ||
1da177e4 | 145 | |
bc56bba8 EB |
146 | /* This is called by fork, once for every shm attach. */ |
147 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 148 | { |
bc56bba8 EB |
149 | struct file *file = vma->vm_file; |
150 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
151 | struct shmid_kernel *shp; |
152 | ||
bc56bba8 | 153 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 154 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 155 | shp->shm_atim = get_seconds(); |
b488893a | 156 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
157 | shp->shm_nattch++; |
158 | shm_unlock(shp); | |
159 | } | |
160 | ||
1da177e4 LT |
161 | /* |
162 | * shm_destroy - free the struct shmid_kernel | |
163 | * | |
f4566f04 | 164 | * @ns: namespace |
1da177e4 LT |
165 | * @shp: struct to free |
166 | * | |
3e148c79 | 167 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
1da177e4 LT |
168 | * but returns with shp unlocked and freed. |
169 | */ | |
4e982311 | 170 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 171 | { |
4e982311 | 172 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 173 | shm_rmid(ns, shp); |
1da177e4 LT |
174 | shm_unlock(shp); |
175 | if (!is_file_hugepages(shp->shm_file)) | |
176 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
353d5c30 | 177 | else if (shp->mlock_user) |
6d63079a | 178 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
179 | shp->mlock_user); |
180 | fput (shp->shm_file); | |
181 | security_shm_free(shp); | |
182 | ipc_rcu_putref(shp); | |
183 | } | |
184 | ||
185 | /* | |
bc56bba8 | 186 | * remove the attach descriptor vma. |
1da177e4 LT |
187 | * free memory for segment if it is marked destroyed. |
188 | * The descriptor has already been removed from the current->mm->mmap list | |
189 | * and will later be kfree()d. | |
190 | */ | |
bc56bba8 | 191 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 192 | { |
bc56bba8 EB |
193 | struct file * file = vma->vm_file; |
194 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 195 | struct shmid_kernel *shp; |
bc56bba8 | 196 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 197 | |
3e148c79 | 198 | down_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 199 | /* remove from the list of attaches of the shm segment */ |
00c2bf85 | 200 | shp = shm_lock(ns, sfd->id); |
023a5355 | 201 | BUG_ON(IS_ERR(shp)); |
b488893a | 202 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
203 | shp->shm_dtim = get_seconds(); |
204 | shp->shm_nattch--; | |
205 | if(shp->shm_nattch == 0 && | |
b33291c0 | 206 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 207 | shm_destroy(ns, shp); |
1da177e4 LT |
208 | else |
209 | shm_unlock(shp); | |
3e148c79 | 210 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
211 | } |
212 | ||
d0217ac0 | 213 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
214 | { |
215 | struct file *file = vma->vm_file; | |
216 | struct shm_file_data *sfd = shm_file_data(file); | |
217 | ||
d0217ac0 | 218 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
219 | } |
220 | ||
221 | #ifdef CONFIG_NUMA | |
d823e3e7 | 222 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
223 | { |
224 | struct file *file = vma->vm_file; | |
225 | struct shm_file_data *sfd = shm_file_data(file); | |
226 | int err = 0; | |
227 | if (sfd->vm_ops->set_policy) | |
228 | err = sfd->vm_ops->set_policy(vma, new); | |
229 | return err; | |
230 | } | |
231 | ||
d823e3e7 AB |
232 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
233 | unsigned long addr) | |
bc56bba8 EB |
234 | { |
235 | struct file *file = vma->vm_file; | |
236 | struct shm_file_data *sfd = shm_file_data(file); | |
237 | struct mempolicy *pol = NULL; | |
238 | ||
239 | if (sfd->vm_ops->get_policy) | |
240 | pol = sfd->vm_ops->get_policy(vma, addr); | |
52cd3b07 | 241 | else if (vma->vm_policy) |
bc56bba8 | 242 | pol = vma->vm_policy; |
52cd3b07 | 243 | |
bc56bba8 EB |
244 | return pol; |
245 | } | |
246 | #endif | |
247 | ||
1da177e4 LT |
248 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
249 | { | |
bc56bba8 | 250 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
251 | int ret; |
252 | ||
bc56bba8 EB |
253 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
254 | if (ret != 0) | |
255 | return ret; | |
256 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 257 | #ifdef CONFIG_MMU |
54cb8821 | 258 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 259 | #endif |
bc56bba8 EB |
260 | vma->vm_ops = &shm_vm_ops; |
261 | shm_open(vma); | |
b0e15190 DH |
262 | |
263 | return ret; | |
1da177e4 LT |
264 | } |
265 | ||
4e982311 KK |
266 | static int shm_release(struct inode *ino, struct file *file) |
267 | { | |
bc56bba8 | 268 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 269 | |
bc56bba8 EB |
270 | put_ipc_ns(sfd->ns); |
271 | shm_file_data(file) = NULL; | |
272 | kfree(sfd); | |
4e982311 KK |
273 | return 0; |
274 | } | |
275 | ||
516dffdc AL |
276 | static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) |
277 | { | |
278 | int (*fsync) (struct file *, struct dentry *, int datasync); | |
279 | struct shm_file_data *sfd = shm_file_data(file); | |
280 | int ret = -EINVAL; | |
281 | ||
282 | fsync = sfd->file->f_op->fsync; | |
283 | if (fsync) | |
284 | ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); | |
285 | return ret; | |
286 | } | |
287 | ||
bc56bba8 EB |
288 | static unsigned long shm_get_unmapped_area(struct file *file, |
289 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
290 | unsigned long flags) | |
291 | { | |
292 | struct shm_file_data *sfd = shm_file_data(file); | |
c4caa778 AV |
293 | return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, |
294 | pgoff, flags); | |
bc56bba8 | 295 | } |
bc56bba8 | 296 | |
9a32144e | 297 | static const struct file_operations shm_file_operations = { |
4e982311 | 298 | .mmap = shm_mmap, |
516dffdc | 299 | .fsync = shm_fsync, |
4e982311 | 300 | .release = shm_release, |
ed5e5894 DH |
301 | #ifndef CONFIG_MMU |
302 | .get_unmapped_area = shm_get_unmapped_area, | |
303 | #endif | |
c4caa778 AV |
304 | }; |
305 | ||
306 | static const struct file_operations shm_file_operations_huge = { | |
307 | .mmap = shm_mmap, | |
308 | .fsync = shm_fsync, | |
309 | .release = shm_release, | |
bc56bba8 | 310 | .get_unmapped_area = shm_get_unmapped_area, |
1da177e4 LT |
311 | }; |
312 | ||
c4caa778 AV |
313 | int is_file_shm_hugepages(struct file *file) |
314 | { | |
315 | return file->f_op == &shm_file_operations_huge; | |
316 | } | |
317 | ||
f0f37e2f | 318 | static const struct vm_operations_struct shm_vm_ops = { |
1da177e4 LT |
319 | .open = shm_open, /* callback for a new vm-area open */ |
320 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 321 | .fault = shm_fault, |
bc56bba8 EB |
322 | #if defined(CONFIG_NUMA) |
323 | .set_policy = shm_set_policy, | |
324 | .get_policy = shm_get_policy, | |
1da177e4 LT |
325 | #endif |
326 | }; | |
327 | ||
f4566f04 ND |
328 | /** |
329 | * newseg - Create a new shared memory segment | |
330 | * @ns: namespace | |
331 | * @params: ptr to the structure that contains key, size and shmflg | |
332 | * | |
3e148c79 | 333 | * Called with shm_ids.rw_mutex held as a writer. |
f4566f04 ND |
334 | */ |
335 | ||
7748dbfa | 336 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 337 | { |
7748dbfa ND |
338 | key_t key = params->key; |
339 | int shmflg = params->flg; | |
340 | size_t size = params->u.size; | |
1da177e4 LT |
341 | int error; |
342 | struct shmid_kernel *shp; | |
343 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
344 | struct file * file; | |
345 | char name[13]; | |
346 | int id; | |
5a6fe125 | 347 | int acctflag = 0; |
1da177e4 | 348 | |
4e982311 | 349 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
350 | return -EINVAL; |
351 | ||
f66d45e9 | 352 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
353 | return -ENOSPC; |
354 | ||
355 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
356 | if (!shp) | |
357 | return -ENOMEM; | |
358 | ||
359 | shp->shm_perm.key = key; | |
b33291c0 | 360 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
361 | shp->mlock_user = NULL; |
362 | ||
363 | shp->shm_perm.security = NULL; | |
364 | error = security_shm_alloc(shp); | |
365 | if (error) { | |
366 | ipc_rcu_putref(shp); | |
367 | return error; | |
368 | } | |
369 | ||
9d66586f | 370 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 371 | if (shmflg & SHM_HUGETLB) { |
5a6fe125 MG |
372 | /* hugetlb_file_setup applies strict accounting */ |
373 | if (shmflg & SHM_NORESERVE) | |
374 | acctflag = VM_NORESERVE; | |
353d5c30 | 375 | file = hugetlb_file_setup(name, size, acctflag, |
6bfde05b | 376 | &shp->mlock_user, HUGETLB_SHMFS_INODE); |
1da177e4 | 377 | } else { |
bf8f972d BP |
378 | /* |
379 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
380 | * if it's asked for. | |
381 | */ | |
382 | if ((shmflg & SHM_NORESERVE) && | |
383 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
fc8744ad | 384 | acctflag = VM_NORESERVE; |
bf8f972d | 385 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
386 | } |
387 | error = PTR_ERR(file); | |
388 | if (IS_ERR(file)) | |
389 | goto no_file; | |
390 | ||
48dea404 | 391 | id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
283bb7fa PP |
392 | if (id < 0) { |
393 | error = id; | |
1da177e4 | 394 | goto no_id; |
283bb7fa | 395 | } |
1da177e4 | 396 | |
b488893a | 397 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
398 | shp->shm_lprid = 0; |
399 | shp->shm_atim = shp->shm_dtim = 0; | |
400 | shp->shm_ctim = get_seconds(); | |
401 | shp->shm_segsz = size; | |
402 | shp->shm_nattch = 0; | |
1da177e4 | 403 | shp->shm_file = file; |
30475cc1 BP |
404 | /* |
405 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
406 | * proc-ps tools use this. Changing this will break them. | |
407 | */ | |
7ca7e564 | 408 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 409 | |
4e982311 | 410 | ns->shm_tot += numpages; |
7ca7e564 | 411 | error = shp->shm_perm.id; |
1da177e4 | 412 | shm_unlock(shp); |
7ca7e564 | 413 | return error; |
1da177e4 LT |
414 | |
415 | no_id: | |
2195d281 | 416 | if (is_file_hugepages(file) && shp->mlock_user) |
353d5c30 | 417 | user_shm_unlock(size, shp->mlock_user); |
1da177e4 LT |
418 | fput(file); |
419 | no_file: | |
420 | security_shm_free(shp); | |
421 | ipc_rcu_putref(shp); | |
422 | return error; | |
423 | } | |
424 | ||
f4566f04 | 425 | /* |
3e148c79 | 426 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 427 | */ |
03f02c76 | 428 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 429 | { |
03f02c76 ND |
430 | struct shmid_kernel *shp; |
431 | ||
432 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
433 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
434 | } |
435 | ||
f4566f04 | 436 | /* |
3e148c79 | 437 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 438 | */ |
03f02c76 ND |
439 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
440 | struct ipc_params *params) | |
7748dbfa | 441 | { |
03f02c76 ND |
442 | struct shmid_kernel *shp; |
443 | ||
444 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
445 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
446 | return -EINVAL; |
447 | ||
448 | return 0; | |
449 | } | |
450 | ||
d5460c99 | 451 | SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) |
1da177e4 | 452 | { |
4e982311 | 453 | struct ipc_namespace *ns; |
7748dbfa ND |
454 | struct ipc_ops shm_ops; |
455 | struct ipc_params shm_params; | |
4e982311 KK |
456 | |
457 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 458 | |
7748dbfa ND |
459 | shm_ops.getnew = newseg; |
460 | shm_ops.associate = shm_security; | |
461 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 462 | |
7748dbfa ND |
463 | shm_params.key = key; |
464 | shm_params.flg = shmflg; | |
465 | shm_params.u.size = size; | |
1da177e4 | 466 | |
7748dbfa | 467 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
468 | } |
469 | ||
470 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
471 | { | |
472 | switch(version) { | |
473 | case IPC_64: | |
474 | return copy_to_user(buf, in, sizeof(*in)); | |
475 | case IPC_OLD: | |
476 | { | |
477 | struct shmid_ds out; | |
478 | ||
479 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); | |
480 | out.shm_segsz = in->shm_segsz; | |
481 | out.shm_atime = in->shm_atime; | |
482 | out.shm_dtime = in->shm_dtime; | |
483 | out.shm_ctime = in->shm_ctime; | |
484 | out.shm_cpid = in->shm_cpid; | |
485 | out.shm_lpid = in->shm_lpid; | |
486 | out.shm_nattch = in->shm_nattch; | |
487 | ||
488 | return copy_to_user(buf, &out, sizeof(out)); | |
489 | } | |
490 | default: | |
491 | return -EINVAL; | |
492 | } | |
493 | } | |
494 | ||
016d7132 PP |
495 | static inline unsigned long |
496 | copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) | |
1da177e4 LT |
497 | { |
498 | switch(version) { | |
499 | case IPC_64: | |
016d7132 | 500 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 501 | return -EFAULT; |
1da177e4 | 502 | return 0; |
1da177e4 LT |
503 | case IPC_OLD: |
504 | { | |
505 | struct shmid_ds tbuf_old; | |
506 | ||
507 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
508 | return -EFAULT; | |
509 | ||
016d7132 PP |
510 | out->shm_perm.uid = tbuf_old.shm_perm.uid; |
511 | out->shm_perm.gid = tbuf_old.shm_perm.gid; | |
512 | out->shm_perm.mode = tbuf_old.shm_perm.mode; | |
1da177e4 LT |
513 | |
514 | return 0; | |
515 | } | |
516 | default: | |
517 | return -EINVAL; | |
518 | } | |
519 | } | |
520 | ||
521 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
522 | { | |
523 | switch(version) { | |
524 | case IPC_64: | |
525 | return copy_to_user(buf, in, sizeof(*in)); | |
526 | case IPC_OLD: | |
527 | { | |
528 | struct shminfo out; | |
529 | ||
530 | if(in->shmmax > INT_MAX) | |
531 | out.shmmax = INT_MAX; | |
532 | else | |
533 | out.shmmax = (int)in->shmmax; | |
534 | ||
535 | out.shmmin = in->shmmin; | |
536 | out.shmmni = in->shmmni; | |
537 | out.shmseg = in->shmseg; | |
538 | out.shmall = in->shmall; | |
539 | ||
540 | return copy_to_user(buf, &out, sizeof(out)); | |
541 | } | |
542 | default: | |
543 | return -EINVAL; | |
544 | } | |
545 | } | |
546 | ||
f4566f04 | 547 | /* |
3e148c79 | 548 | * Called with shm_ids.rw_mutex held as a reader |
f4566f04 | 549 | */ |
4e982311 KK |
550 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
551 | unsigned long *swp) | |
1da177e4 | 552 | { |
7ca7e564 ND |
553 | int next_id; |
554 | int total, in_use; | |
1da177e4 LT |
555 | |
556 | *rss = 0; | |
557 | *swp = 0; | |
558 | ||
7ca7e564 ND |
559 | in_use = shm_ids(ns).in_use; |
560 | ||
561 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
e562aebc | 562 | struct kern_ipc_perm *ipc; |
1da177e4 LT |
563 | struct shmid_kernel *shp; |
564 | struct inode *inode; | |
565 | ||
e562aebc TB |
566 | ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
567 | if (ipc == NULL) | |
1da177e4 | 568 | continue; |
e562aebc | 569 | shp = container_of(ipc, struct shmid_kernel, shm_perm); |
1da177e4 | 570 | |
6d63079a | 571 | inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4 LT |
572 | |
573 | if (is_file_hugepages(shp->shm_file)) { | |
574 | struct address_space *mapping = inode->i_mapping; | |
a5516438 AK |
575 | struct hstate *h = hstate_file(shp->shm_file); |
576 | *rss += pages_per_huge_page(h) * mapping->nrpages; | |
1da177e4 | 577 | } else { |
a68e61e8 | 578 | #ifdef CONFIG_SHMEM |
1da177e4 LT |
579 | struct shmem_inode_info *info = SHMEM_I(inode); |
580 | spin_lock(&info->lock); | |
581 | *rss += inode->i_mapping->nrpages; | |
582 | *swp += info->swapped; | |
583 | spin_unlock(&info->lock); | |
a68e61e8 TB |
584 | #else |
585 | *rss += inode->i_mapping->nrpages; | |
586 | #endif | |
1da177e4 | 587 | } |
7ca7e564 ND |
588 | |
589 | total++; | |
1da177e4 LT |
590 | } |
591 | } | |
592 | ||
8d4cc8b5 PP |
593 | /* |
594 | * This function handles some shmctl commands which require the rw_mutex | |
595 | * to be held in write mode. | |
596 | * NOTE: no locks must be held, the rw_mutex is taken inside this function. | |
597 | */ | |
598 | static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, | |
599 | struct shmid_ds __user *buf, int version) | |
1da177e4 | 600 | { |
8d4cc8b5 | 601 | struct kern_ipc_perm *ipcp; |
016d7132 | 602 | struct shmid64_ds shmid64; |
8d4cc8b5 PP |
603 | struct shmid_kernel *shp; |
604 | int err; | |
605 | ||
606 | if (cmd == IPC_SET) { | |
016d7132 | 607 | if (copy_shmid_from_user(&shmid64, buf, version)) |
8d4cc8b5 PP |
608 | return -EFAULT; |
609 | } | |
610 | ||
a5f75e7f PP |
611 | ipcp = ipcctl_pre_down(&shm_ids(ns), shmid, cmd, &shmid64.shm_perm, 0); |
612 | if (IS_ERR(ipcp)) | |
613 | return PTR_ERR(ipcp); | |
8d4cc8b5 | 614 | |
a5f75e7f | 615 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
8d4cc8b5 PP |
616 | |
617 | err = security_shm_shmctl(shp, cmd); | |
618 | if (err) | |
619 | goto out_unlock; | |
620 | switch (cmd) { | |
621 | case IPC_RMID: | |
622 | do_shm_rmid(ns, ipcp); | |
623 | goto out_up; | |
624 | case IPC_SET: | |
8f4a3809 | 625 | ipc_update_perm(&shmid64.shm_perm, ipcp); |
8d4cc8b5 PP |
626 | shp->shm_ctim = get_seconds(); |
627 | break; | |
628 | default: | |
629 | err = -EINVAL; | |
630 | } | |
631 | out_unlock: | |
632 | shm_unlock(shp); | |
633 | out_up: | |
634 | up_write(&shm_ids(ns).rw_mutex); | |
635 | return err; | |
636 | } | |
637 | ||
d5460c99 | 638 | SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) |
8d4cc8b5 | 639 | { |
1da177e4 LT |
640 | struct shmid_kernel *shp; |
641 | int err, version; | |
4e982311 | 642 | struct ipc_namespace *ns; |
1da177e4 LT |
643 | |
644 | if (cmd < 0 || shmid < 0) { | |
645 | err = -EINVAL; | |
646 | goto out; | |
647 | } | |
648 | ||
649 | version = ipc_parse_version(&cmd); | |
4e982311 | 650 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
651 | |
652 | switch (cmd) { /* replace with proc interface ? */ | |
653 | case IPC_INFO: | |
654 | { | |
655 | struct shminfo64 shminfo; | |
656 | ||
657 | err = security_shm_shmctl(NULL, cmd); | |
658 | if (err) | |
659 | return err; | |
660 | ||
e8148f75 | 661 | memset(&shminfo, 0, sizeof(shminfo)); |
4e982311 KK |
662 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
663 | shminfo.shmmax = ns->shm_ctlmax; | |
664 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
665 | |
666 | shminfo.shmmin = SHMMIN; | |
667 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
668 | return -EFAULT; | |
f4566f04 | 669 | |
3e148c79 | 670 | down_read(&shm_ids(ns).rw_mutex); |
7ca7e564 | 671 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 672 | up_read(&shm_ids(ns).rw_mutex); |
f4566f04 | 673 | |
1da177e4 LT |
674 | if(err<0) |
675 | err = 0; | |
676 | goto out; | |
677 | } | |
678 | case SHM_INFO: | |
679 | { | |
680 | struct shm_info shm_info; | |
681 | ||
682 | err = security_shm_shmctl(NULL, cmd); | |
683 | if (err) | |
684 | return err; | |
685 | ||
e8148f75 | 686 | memset(&shm_info, 0, sizeof(shm_info)); |
3e148c79 | 687 | down_read(&shm_ids(ns).rw_mutex); |
4e982311 KK |
688 | shm_info.used_ids = shm_ids(ns).in_use; |
689 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
690 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
691 | shm_info.swap_attempts = 0; |
692 | shm_info.swap_successes = 0; | |
7ca7e564 | 693 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 694 | up_read(&shm_ids(ns).rw_mutex); |
e8148f75 | 695 | if (copy_to_user(buf, &shm_info, sizeof(shm_info))) { |
1da177e4 LT |
696 | err = -EFAULT; |
697 | goto out; | |
698 | } | |
699 | ||
700 | err = err < 0 ? 0 : err; | |
701 | goto out; | |
702 | } | |
703 | case SHM_STAT: | |
704 | case IPC_STAT: | |
705 | { | |
706 | struct shmid64_ds tbuf; | |
707 | int result; | |
023a5355 | 708 | |
023a5355 ND |
709 | if (cmd == SHM_STAT) { |
710 | shp = shm_lock(ns, shmid); | |
711 | if (IS_ERR(shp)) { | |
712 | err = PTR_ERR(shp); | |
713 | goto out; | |
714 | } | |
7ca7e564 | 715 | result = shp->shm_perm.id; |
1da177e4 | 716 | } else { |
023a5355 ND |
717 | shp = shm_lock_check(ns, shmid); |
718 | if (IS_ERR(shp)) { | |
719 | err = PTR_ERR(shp); | |
720 | goto out; | |
721 | } | |
1da177e4 LT |
722 | result = 0; |
723 | } | |
e8148f75 | 724 | err = -EACCES; |
1da177e4 LT |
725 | if (ipcperms (&shp->shm_perm, S_IRUGO)) |
726 | goto out_unlock; | |
727 | err = security_shm_shmctl(shp, cmd); | |
728 | if (err) | |
729 | goto out_unlock; | |
023a5355 | 730 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
731 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
732 | tbuf.shm_segsz = shp->shm_segsz; | |
733 | tbuf.shm_atime = shp->shm_atim; | |
734 | tbuf.shm_dtime = shp->shm_dtim; | |
735 | tbuf.shm_ctime = shp->shm_ctim; | |
736 | tbuf.shm_cpid = shp->shm_cprid; | |
737 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 738 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
739 | shm_unlock(shp); |
740 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
741 | err = -EFAULT; | |
742 | else | |
743 | err = result; | |
744 | goto out; | |
745 | } | |
746 | case SHM_LOCK: | |
747 | case SHM_UNLOCK: | |
748 | { | |
89e004ea LS |
749 | struct file *uninitialized_var(shm_file); |
750 | ||
751 | lru_add_drain_all(); /* drain pagevecs to lru lists */ | |
752 | ||
023a5355 ND |
753 | shp = shm_lock_check(ns, shmid); |
754 | if (IS_ERR(shp)) { | |
755 | err = PTR_ERR(shp); | |
1da177e4 LT |
756 | goto out; |
757 | } | |
1da177e4 | 758 | |
a33e6751 | 759 | audit_ipc_obj(&(shp->shm_perm)); |
073115d6 | 760 | |
1da177e4 | 761 | if (!capable(CAP_IPC_LOCK)) { |
414c0708 | 762 | uid_t euid = current_euid(); |
1da177e4 | 763 | err = -EPERM; |
414c0708 DH |
764 | if (euid != shp->shm_perm.uid && |
765 | euid != shp->shm_perm.cuid) | |
1da177e4 | 766 | goto out_unlock; |
f1eb1332 | 767 | if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) |
1da177e4 LT |
768 | goto out_unlock; |
769 | } | |
770 | ||
771 | err = security_shm_shmctl(shp, cmd); | |
772 | if (err) | |
773 | goto out_unlock; | |
774 | ||
775 | if(cmd==SHM_LOCK) { | |
86a264ab | 776 | struct user_struct *user = current_user(); |
1da177e4 LT |
777 | if (!is_file_hugepages(shp->shm_file)) { |
778 | err = shmem_lock(shp->shm_file, 1, user); | |
7be77e20 | 779 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0 | 780 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
781 | shp->mlock_user = user; |
782 | } | |
783 | } | |
784 | } else if (!is_file_hugepages(shp->shm_file)) { | |
785 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 786 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
787 | shp->mlock_user = NULL; |
788 | } | |
789 | shm_unlock(shp); | |
790 | goto out; | |
791 | } | |
792 | case IPC_RMID: | |
1da177e4 | 793 | case IPC_SET: |
8d4cc8b5 PP |
794 | err = shmctl_down(ns, shmid, cmd, buf, version); |
795 | return err; | |
1da177e4 | 796 | default: |
8d4cc8b5 | 797 | return -EINVAL; |
1da177e4 LT |
798 | } |
799 | ||
1da177e4 LT |
800 | out_unlock: |
801 | shm_unlock(shp); | |
802 | out: | |
803 | return err; | |
804 | } | |
805 | ||
806 | /* | |
807 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
808 | * | |
809 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
810 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
811 | * this. | |
812 | */ | |
813 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
814 | { | |
815 | struct shmid_kernel *shp; | |
816 | unsigned long addr; | |
817 | unsigned long size; | |
818 | struct file * file; | |
819 | int err; | |
820 | unsigned long flags; | |
821 | unsigned long prot; | |
1da177e4 | 822 | int acc_mode; |
bc56bba8 | 823 | unsigned long user_addr; |
4e982311 | 824 | struct ipc_namespace *ns; |
bc56bba8 EB |
825 | struct shm_file_data *sfd; |
826 | struct path path; | |
aeb5d727 | 827 | fmode_t f_mode; |
1da177e4 | 828 | |
bc56bba8 EB |
829 | err = -EINVAL; |
830 | if (shmid < 0) | |
1da177e4 | 831 | goto out; |
bc56bba8 | 832 | else if ((addr = (ulong)shmaddr)) { |
1da177e4 LT |
833 | if (addr & (SHMLBA-1)) { |
834 | if (shmflg & SHM_RND) | |
835 | addr &= ~(SHMLBA-1); /* round down */ | |
836 | else | |
837 | #ifndef __ARCH_FORCE_SHMLBA | |
838 | if (addr & ~PAGE_MASK) | |
839 | #endif | |
bc56bba8 | 840 | goto out; |
1da177e4 LT |
841 | } |
842 | flags = MAP_SHARED | MAP_FIXED; | |
843 | } else { | |
844 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 845 | goto out; |
1da177e4 LT |
846 | |
847 | flags = MAP_SHARED; | |
848 | } | |
849 | ||
850 | if (shmflg & SHM_RDONLY) { | |
851 | prot = PROT_READ; | |
1da177e4 | 852 | acc_mode = S_IRUGO; |
bc56bba8 | 853 | f_mode = FMODE_READ; |
1da177e4 LT |
854 | } else { |
855 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 856 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 857 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
858 | } |
859 | if (shmflg & SHM_EXEC) { | |
860 | prot |= PROT_EXEC; | |
861 | acc_mode |= S_IXUGO; | |
862 | } | |
863 | ||
864 | /* | |
865 | * We cannot rely on the fs check since SYSV IPC does have an | |
866 | * additional creator id... | |
867 | */ | |
4e982311 | 868 | ns = current->nsproxy->ipc_ns; |
023a5355 ND |
869 | shp = shm_lock_check(ns, shmid); |
870 | if (IS_ERR(shp)) { | |
871 | err = PTR_ERR(shp); | |
1da177e4 | 872 | goto out; |
023a5355 | 873 | } |
bc56bba8 EB |
874 | |
875 | err = -EACCES; | |
876 | if (ipcperms(&shp->shm_perm, acc_mode)) | |
877 | goto out_unlock; | |
1da177e4 LT |
878 | |
879 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
880 | if (err) |
881 | goto out_unlock; | |
882 | ||
2c48b9c4 AV |
883 | path = shp->shm_file->f_path; |
884 | path_get(&path); | |
1da177e4 | 885 | shp->shm_nattch++; |
bc56bba8 | 886 | size = i_size_read(path.dentry->d_inode); |
1da177e4 LT |
887 | shm_unlock(shp); |
888 | ||
bc56bba8 EB |
889 | err = -ENOMEM; |
890 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
891 | if (!sfd) | |
ce8d2cdf | 892 | goto out_put_dentry; |
bc56bba8 | 893 | |
2c48b9c4 AV |
894 | file = alloc_file(&path, f_mode, |
895 | is_file_hugepages(shp->shm_file) ? | |
c4caa778 AV |
896 | &shm_file_operations_huge : |
897 | &shm_file_operations); | |
bc56bba8 EB |
898 | if (!file) |
899 | goto out_free; | |
900 | ||
bc56bba8 | 901 | file->private_data = sfd; |
bc56bba8 | 902 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 903 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
904 | sfd->ns = get_ipc_ns(ns); |
905 | sfd->file = shp->shm_file; | |
906 | sfd->vm_ops = NULL; | |
907 | ||
1da177e4 LT |
908 | down_write(¤t->mm->mmap_sem); |
909 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 910 | err = -EINVAL; |
1da177e4 LT |
911 | if (find_vma_intersection(current->mm, addr, addr + size)) |
912 | goto invalid; | |
913 | /* | |
914 | * If shm segment goes below stack, make sure there is some | |
915 | * space left for the stack to grow (at least 4 pages). | |
916 | */ | |
917 | if (addr < current->mm->start_stack && | |
918 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
919 | goto invalid; | |
920 | } | |
921 | ||
bc56bba8 EB |
922 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
923 | *raddr = user_addr; | |
924 | err = 0; | |
925 | if (IS_ERR_VALUE(user_addr)) | |
926 | err = (long)user_addr; | |
1da177e4 LT |
927 | invalid: |
928 | up_write(¤t->mm->mmap_sem); | |
929 | ||
bc56bba8 EB |
930 | fput(file); |
931 | ||
932 | out_nattch: | |
3e148c79 | 933 | down_write(&shm_ids(ns).rw_mutex); |
00c2bf85 | 934 | shp = shm_lock(ns, shmid); |
023a5355 | 935 | BUG_ON(IS_ERR(shp)); |
1da177e4 LT |
936 | shp->shm_nattch--; |
937 | if(shp->shm_nattch == 0 && | |
b33291c0 | 938 | shp->shm_perm.mode & SHM_DEST) |
4e982311 | 939 | shm_destroy(ns, shp); |
1da177e4 LT |
940 | else |
941 | shm_unlock(shp); | |
3e148c79 | 942 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 943 | |
1da177e4 LT |
944 | out: |
945 | return err; | |
bc56bba8 EB |
946 | |
947 | out_unlock: | |
948 | shm_unlock(shp); | |
949 | goto out; | |
950 | ||
951 | out_free: | |
952 | kfree(sfd); | |
ce8d2cdf | 953 | out_put_dentry: |
2c48b9c4 | 954 | path_put(&path); |
bc56bba8 | 955 | goto out_nattch; |
1da177e4 LT |
956 | } |
957 | ||
d5460c99 | 958 | SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) |
7d87e14c SR |
959 | { |
960 | unsigned long ret; | |
961 | long err; | |
962 | ||
963 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
964 | if (err) | |
965 | return err; | |
966 | force_successful_syscall_return(); | |
967 | return (long)ret; | |
968 | } | |
969 | ||
1da177e4 LT |
970 | /* |
971 | * detach and kill segment if marked destroyed. | |
972 | * The work is done in shm_close. | |
973 | */ | |
d5460c99 | 974 | SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) |
1da177e4 LT |
975 | { |
976 | struct mm_struct *mm = current->mm; | |
586c7e6a | 977 | struct vm_area_struct *vma; |
1da177e4 | 978 | unsigned long addr = (unsigned long)shmaddr; |
1da177e4 | 979 | int retval = -EINVAL; |
586c7e6a MF |
980 | #ifdef CONFIG_MMU |
981 | loff_t size = 0; | |
982 | struct vm_area_struct *next; | |
983 | #endif | |
1da177e4 | 984 | |
df1e2fb5 HD |
985 | if (addr & ~PAGE_MASK) |
986 | return retval; | |
987 | ||
1da177e4 LT |
988 | down_write(&mm->mmap_sem); |
989 | ||
990 | /* | |
991 | * This function tries to be smart and unmap shm segments that | |
992 | * were modified by partial mlock or munmap calls: | |
993 | * - It first determines the size of the shm segment that should be | |
994 | * unmapped: It searches for a vma that is backed by shm and that | |
995 | * started at address shmaddr. It records it's size and then unmaps | |
996 | * it. | |
997 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
998 | * are within the initially determined size. | |
999 | * Errors from do_munmap are ignored: the function only fails if | |
1000 | * it's called with invalid parameters or if it's called to unmap | |
1001 | * a part of a vma. Both calls in this function are for full vmas, | |
1002 | * the parameters are directly copied from the vma itself and always | |
1003 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1004 | */ | |
1005 | /* | |
1006 | * If it had been mremap()'d, the starting address would not | |
1007 | * match the usual checks anyway. So assume all vma's are | |
1008 | * above the starting address given. | |
1009 | */ | |
1010 | vma = find_vma(mm, addr); | |
1011 | ||
8feae131 | 1012 | #ifdef CONFIG_MMU |
1da177e4 LT |
1013 | while (vma) { |
1014 | next = vma->vm_next; | |
1015 | ||
1016 | /* | |
1017 | * Check if the starting address would match, i.e. it's | |
1018 | * a fragment created by mprotect() and/or munmap(), or it | |
1019 | * otherwise it starts at this address with no hassles. | |
1020 | */ | |
bc56bba8 | 1021 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1022 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1023 | ||
1024 | ||
6d63079a | 1025 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1026 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1027 | /* | |
1028 | * We discovered the size of the shm segment, so | |
1029 | * break out of here and fall through to the next | |
1030 | * loop that uses the size information to stop | |
1031 | * searching for matching vma's. | |
1032 | */ | |
1033 | retval = 0; | |
1034 | vma = next; | |
1035 | break; | |
1036 | } | |
1037 | vma = next; | |
1038 | } | |
1039 | ||
1040 | /* | |
1041 | * We need look no further than the maximum address a fragment | |
1042 | * could possibly have landed at. Also cast things to loff_t to | |
1043 | * prevent overflows and make comparisions vs. equal-width types. | |
1044 | */ | |
8e36709d | 1045 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1046 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1047 | next = vma->vm_next; | |
1048 | ||
1049 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1050 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1051 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1052 | ||
1053 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1054 | vma = next; | |
1055 | } | |
1056 | ||
8feae131 DH |
1057 | #else /* CONFIG_MMU */ |
1058 | /* under NOMMU conditions, the exact address to be destroyed must be | |
1059 | * given */ | |
1060 | retval = -EINVAL; | |
1061 | if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { | |
1062 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1063 | retval = 0; | |
1064 | } | |
1065 | ||
1066 | #endif | |
1067 | ||
1da177e4 LT |
1068 | up_write(&mm->mmap_sem); |
1069 | return retval; | |
1070 | } | |
1071 | ||
1072 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1073 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1074 | { |
19b4946c | 1075 | struct shmid_kernel *shp = it; |
1da177e4 | 1076 | |
6c826818 PM |
1077 | #if BITS_PER_LONG <= 32 |
1078 | #define SIZE_SPEC "%10lu" | |
1079 | #else | |
1080 | #define SIZE_SPEC "%21lu" | |
1081 | #endif | |
1da177e4 | 1082 | |
6c826818 PM |
1083 | return seq_printf(s, |
1084 | "%10d %10d %4o " SIZE_SPEC " %5u %5u " | |
1085 | "%5lu %5u %5u %5u %5u %10lu %10lu %10lu\n", | |
19b4946c | 1086 | shp->shm_perm.key, |
7ca7e564 | 1087 | shp->shm_perm.id, |
b33291c0 | 1088 | shp->shm_perm.mode, |
19b4946c MW |
1089 | shp->shm_segsz, |
1090 | shp->shm_cprid, | |
1091 | shp->shm_lprid, | |
bc56bba8 | 1092 | shp->shm_nattch, |
19b4946c MW |
1093 | shp->shm_perm.uid, |
1094 | shp->shm_perm.gid, | |
1095 | shp->shm_perm.cuid, | |
1096 | shp->shm_perm.cgid, | |
1097 | shp->shm_atim, | |
1098 | shp->shm_dtim, | |
1099 | shp->shm_ctim); | |
1da177e4 LT |
1100 | } |
1101 | #endif |